My key takeaway from here is to have a dedicated email for gambling related activities. I use more than one emails for different gambling sites and it is difficult to tracked where issues like this originates from.
It might be complicated to have different emails for different casinos except you have to record the details and keep them safe. But it the better than having just one email. People who usually use one email different casinos might have security issues in all the casinos of one other thier account is compromised. A hacker or scammer can easily access other casinos if they have access to one.